<!DOCTYPE html>
<html>
    <head>
        <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/>
        <title>JavaScriptSat</title>
        <script type="text/javascript">                
          setInterval(function () { sat(); }, 1000);
             function sat() {            
              var datum = new Date();
              document.f1.it1.value = datum.toLocaleString();
          }
        </script>
    </head>
    <body>
        <form name="f1">
            <input id="it1"/>
        </form>
    </body>
</html>